On Tuesday, January 28, 2020 at 11:57:08 AM UTC-7, John Clark wrote: > > On Tue, Jan 28, 2020 at 1:28 PM Alan Grayson <[email protected] > <javascript:>> wrote: > > *> For the observer situated in a distant galaxy, his clock does not >> dilate, and his length does not contract. * > > > Alan, we know from the redshift that clocks at cosmological distances do NOT > all run at the same rate, so if you didn't also have length contraction > there is no way all observers could measure the same speed for light. You > must have both. >
*I'm confused about what relativity tells us. I'd like some input from Brent. We know that orbital clocks do not run at the same rate as ground clocks, so the effect is objective, not merely apparent. So do clocks in distant galaxies run objectively slower than clocks in our galaxy (as orbiting clocks do compared to ground clocks) based on the cosmological red shift, and are their masses increasing since they're moving close to light speed? I am not sure. AG* > > > those galaxies would NOT shrink in length to zero, > > > But that contradicts your previous post, you said there were no > discontinuities and length contraction, time dilation, and mass increase > continuously and does not stop suddenly at some point short of the speed > of light. Einstein says from our viewpoint distant galaxies can be > arbitrarily thin and the clocks in them can be arbitrarily slow. What do > you say? > *I say you're wrong. You're implicitly claiming we can measure these variables in the NON-observable region, but you know this is impossible. Further, since the universe has been expanding for finite time, if it's spherical, it's must be finite in volume. I don't see any way around this conclusion. **The assumption that it continues to expand forever might be correct, but at any time t, determined by the physical clock of the CMBR, its volume is finite. AG* *The mass is also finite since no mass is being created as it expands. OTOH, since distant galaxies within our observable region are receding close to light speed, you might conclude their mass is increasing. I am not sure how to resolve this issue. Perhaps if the relative velocities are caused by the expansion of space, and NOT due to relative kinematic motion, conclusions based on the cosmological red shift are invalid. I am not sure what's going here. I think Brent can resolve this issue. AG* John K Clark > >> >> -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/08ba6e2e-f56e-492c-8ad9-df2831a0bdb1%40googlegroups.com.
